diff --git a/test/irc/test_irc_capabilities.py b/test/irc/test_irc_capabilities.py
index 2a4e6d042..b24c9aa1f 100644
--- a/test/irc/test_irc_capabilities.py
+++ b/test/irc/test_irc_capabilities.py
@@ -83,6 +83,20 @@ def test_capabilities_ls_multiline(mockbot, triggerfactory):
     assert manager.available == {'away-notify': None, 'account-tag': None}
 
 
+def test_capabilities_ls_trailing_space(mockbot, triggerfactory: TriggerFactory):
+    raw = 'CAP * LS :away-notify '
+    wrapped = triggerfactory.wrapper(mockbot, raw)
+    manager = Capabilities()
+    assert manager.handle_ls(wrapped, wrapped._trigger)
+    assert manager.is_available('away-notify')
+    assert not manager.is_enabled('away-notify')
+    assert manager.available == {'away-notify': None}
+    assert not manager.enabled
+
+    expected = CapabilityInfo('away-notify', None, True, False)
+    assert manager.get_capability_info('away-notify') == expected
+
+
 def test_capabilities_ack(mockbot, triggerfactory):
     raw = 'CAP * ACK :away-notify'
     wrapped = triggerfactory.wrapper(mockbot, raw)
@@ -104,6 +118,18 @@ def test_capabilities_ack(mockbot, triggerfactory):
     assert manager.enabled == frozenset({'away-notify', 'account-tag'})
 
 
+def test_capabilities_ack_trailing_space(mockbot, triggerfactory):
+    raw = 'CAP * ACK :away-notify '
+    wrapped = triggerfactory.wrapper(mockbot, raw)
+    manager = Capabilities()
+    assert manager.handle_ack(wrapped, wrapped._trigger) == ('away-notify',)
+    assert not manager.is_available('away-notify'), (
+        'ACK a capability does not update server availability.')
+    assert manager.is_enabled('away-notify'), (
+        'ACK a capability make it enabled.')
+    assert manager.enabled == frozenset({'away-notify'})
+
+
 def test_capabilities_ack_multiple(mockbot, triggerfactory):
     raw = 'CAP * ACK :away-notify account-tag'
     wrapped = triggerfactory.wrapper(mockbot, raw)
@@ -183,7 +209,19 @@ def test_capabilities_nak(mockbot, triggerfactory):
     assert not manager.enabled
 
 
-def test_capabilities_nack_multiple(mockbot, triggerfactory):
+def test_capabilities_nak_trailing_space(mockbot, triggerfactory):
+    raw = 'CAP * NAK :away-notify '
+    wrapped = triggerfactory.wrapper(mockbot, raw)
+    manager = Capabilities()
+    assert manager.handle_nak(wrapped, wrapped._trigger) == ('away-notify',)
+    assert not manager.is_available('away-notify'), (
+        'NAK a capability does not update server availability.')
+    assert not manager.is_enabled('away-notify'), (
+        'NAK a capability make it not enabled.')
+    assert not manager.enabled
+
+
+def test_capabilities_nak_multiple(mockbot, triggerfactory):
     raw = 'CAP * NAK :away-notify account-tag'
     wrapped = triggerfactory.wrapper(mockbot, raw)
     manager = Capabilities()
@@ -208,7 +246,7 @@ def test_capabilities_nack_multiple(mockbot, triggerfactory):
     assert not manager.enabled
 
 
-def test_capabilities_ack_and_nack(mockbot, triggerfactory):
+def test_capabilities_ack_and_nak(mockbot, triggerfactory):
     manager = Capabilities()
 
     # ACK a single CAP
@@ -274,6 +312,21 @@ def test_capabilities_new(mockbot, triggerfactory):
     assert not manager.enabled
 
 
+def test_capabilities_new_trailing_space(mockbot, triggerfactory):
+    manager = Capabilities()
+
+    # NEW CAP
+    raw = 'CAP * NEW :echo-message '
+    wrapped = triggerfactory.wrapper(mockbot, raw)
+    assert manager.handle_new(wrapped, wrapped._trigger) == (
+        'echo-message',
+    )
+    assert manager.is_available('echo-message')
+    assert not manager.is_enabled('echo-message')
+    assert manager.available == {'echo-message': None}
+    assert not manager.enabled
+
+
 def test_capabilities_new_multiple(mockbot, triggerfactory):
     manager = Capabilities()
 
@@ -320,6 +373,21 @@ def test_capabilities_del(mockbot, triggerfactory):
     assert not manager.enabled
 
 
+def test_capabilities_del_trailing_space(mockbot, triggerfactory):
+    manager = Capabilities()
+
+    # DEL CAP
+    raw = 'CAP * DEL :echo-message '
+    wrapped = triggerfactory.wrapper(mockbot, raw)
+    assert manager.handle_del(wrapped, wrapped._trigger) == (
+        'echo-message',
+    )
+    assert not manager.is_available('echo-message')
+    assert not manager.is_enabled('echo-message')
+    assert not manager.available
+    assert not manager.enabled
+
+
 def test_capabilities_del_available(mockbot, triggerfactory):
     manager = Capabilities()